Centrifugal operating mechanism



Dec 11, 1928. 1,694,700 W. J. BRANSQN CENTRIFUGAL OPERATING MECHANISM Filed Sept. 28, 1926 INVENTOR.

ATTORNEYS.

Patented Dec. 11, 1928.

UNITED STATES PATENT OFFICE.

WALTER J. BRANSON, OF SPRINGFIELD, OHIO, ASSIGNOB, BY MESNE ASSIGNMENTS, TO ROBBINS & MYERS, INC., 01 SPRINGFIELD, OHIO, A CORPORATION OF OHIO.

CENTBIFUGAL OPERATING MECHANISM.

Application filed September 28, 1926. Serial No, 188,305.

This invention relates to centrifugal operating mechanism in which weights are employed, it particularly relating to means for reducing the friction between the welghts and the parts with which they cooperate.

The object of the invention is to provide an arrangement for reducing the friction between the centrifugally operated weights and the parts with which they cooperate; a fur- 1 ther and more specific object in this connec tion being to provide anti-friction balls which are movable with the weights and are interposed between the weights and the co-- operating parts.

In the accompanying drawings:

Fig. 1 is a view partly in side elevatlon and partly in longitudinal section of a mechanism embodying the improvements.

Fig. 2 is an elevation of the inner faces of the weights and their enclosing guard casing, showing the motor shaft and the hub upon which the weights and guard are mounted in section.

In the present exemplification of the invention, I have illustrated my improved mechanism as constituting a part of short circuiting devices for electric motors of the repulsion induction type, but it is to be understood that this mechanism is applicable to other purposes.

Referring to the drawings, 1 represents the shaft of the motor to which my improved devices are applied and 2 the commutator. A hub 3 is secured to the shaft so as to rotate therewith, preferably by keying, and this hub is held against longitudinal displacement in one direction by the commutatorand in the other by a spring clip 4 fitted in the groove 5' in the shaft. Slidably mounted upon the hub is a sleeve 6 having at its outer end an integral inclined annular flange 6. Secured to the outer end of the hub is a cupshaped casing 7 to form a guard, the end wall of this casing being bent inwardl as indicated at 7 to form an inclined sur ace which cooperates with the inclined flange 6' to provide a throat or space which converges outwardly. A series of weights 8 of segmental form, in the present case three in number, are provided about the hub 3, the surface of the base portion of each of these weights being inclined as indicated at 9to conform to the inclined face 7 of the guard and the inclined face 6 of the flange, between which the bases of the weights are located. Each of the weights near its inner edge is provided with open-ended pockets 10, each segment being preferably provided with two of these pockets. Within each pocket is located a pair of balls 11, protruding slightly from the ends thereof, which are arranged to have a rolling contact with each other and with respectively inclined surfaces 7 and 6 as the wei hts move'outwardly and inwardly.

ounted upon the sleeve 6 and against the flange thereof is a collar 12 of insulating material and mounted upon this collar 12 is an annular contact plate 13, the sleeve and its inclined flange, the collar and the plate constituting one form of a movable contact device. The inclined surface 6 of the sleeve 6 is held in contact with the inner balls 11 by a coil spring 14 which is interposed between the collar 12 and a washer 15 on the rear end of the hub 3.

The operation is as follows: As the speed of the motor increases the weights 8 are thrown outwardly by centrifugal force so as to move the sleeve 6, collar 12 and contact plate axially to bring the plate in contact with the commutator bars. During this movement the balls 11 rotate so that the balls not onlyroll upon each other, but the inner balls will roll upo'. the inclined surface 6 and the outer balls upon the inclined surface 7 thus materially reducing'the friction between the weights and the inclined surfaces with which they cooperate. Further, by this arrangement, when the motor stops, the weights move readily back to their inner positions by the ac tion of the spring.

By this arrangement a compact structure is secured in which the weights act as retainers for, the balls in such a way that there is no danger of the balls jumping or flying out from between the contact surfaces. Further, by this arrangement the balls constantly seek new paths on the inclined surfaces to thereby distribute the wear around the entire surface of theinclined members obviating the formation of grooves which would act to give an irregular action to the movement of the parts so'that the mechanism will always operate accurately at any given speed; this result being further accomplished by reason of the fact that the balls have a rolling action upon the inclined surfaces. This rolling action also insures a uniform friction upon the inclined surfaces so that the devices will operate uniformly at given speeds.

' -Having thus described my invention, I claim: 7

1. Ina centrifugal operating mechanism, a rotatable member, a plurality of freelyfloating weights rotatable therewith and movable radially outwardly by centrifugal force, each of said weights having a pair of anti-friction balls in rolling contact with each other, a member having a surface on one side of said weights co-operating with one of the balls of each pair, and a spring pressed axially movable member on the opposite side of said weights having a surface in contact with the other ball of each pair, each of said surfaces being inclined with the surfaces coning weights between said inclined surfaces,

each of said weights having a pair of antifrictioh balls in rolling contact with each other and with the respective inclined surfaces. 1

3. In a centrifugal operating mechanism, a

rotatable member, a plurality of radiallymovable freely-floating weights rotatable therewith and movable outwardly by centrifugal force, each of said weights having a plurality of open-ended pockets, a pair of balls in each ocket in rolling contact with each other wit the balls protruding slightly from the ends of said pockets, inclined members on the respective sides of said weights one of which is movable axially of the rotatable member, the inclination of said members extending uniformly about the entire faces of said members, and a spring for holding said inclined members and said balls in contact. a

4. In a centrifugal operating mechanism, a rotatable member, a plurality of segmental freely-floating weights arranged consecutively about said member and movable outwardly by centrifugal force, each of said weights having a plurality of openings near the inner portion thereof extending entirely through the same in an axial direction, a pair of balls in each pocket in rolling contact with each other and protruding slightly from the open ends thereof, a pair of inclined members oneach side of said weights, one of which is axially movable and the other of which is held from axial movement, the inclinations of said members extending uniformly about the entire faces thereof, and a spring cooperating with the axially movable member to normally press the same toward the other member.

In testimony whereof, I have hereunto set my hand this 16th day of September 1926.

WALTER J. BRANSON. 

